Functionalized ZnO nanoparticles for thin-film transistors : support of ligand removal by non-thermal methods

A new approach is presented which allows substantial reduction of the process temperature of zinc oxide nanoparticles to generate semiconducting thin films. Functionalization is used to allow facile dispersion and to prevent agglomeration of the particles. Since charge transport is impeded by an insulating shell of octylamine the functionalization needs to be removed. Particles are deposited by spin-coating and the resulting film is exposed to different treatments. It is shown that plain annealing processes require high temperatures to fully remove the capping agents. The method presented in this work is a combination of UV irradiation of the wet films before annealing to cleave the octylamine and a vacuum process to aid the removal of organic residues. The effectiveness of the method is proven by electrical characterization.